Bimolecular Fluorescence Complementation Assay:Application in The Study of Protein-protein Interaction / 生物化学与生物物理进展

Bimolecular fluorescence complementation (BiFC) assay is an innovative approach to investigate protein interactions, based on the reassembly of protein fragments of the fluorescent proteins which directly report interactions. The fluorescent proteins tolerate circular permutation and insertions of foreign proteins with maintenance of fluorescence. So when the proteins fused to the reporter fragments interact with each other, a direct readout of the association would be given from the facilitating reassembly of the active reporter protein. Moreover, with distinct spectra difference of the fluorescent protein family members, BiFC assay is expanded to multicolor BiFC assay which enables visualization of interactions between different proteins in the same cell and comparison of the efficiencies of complex formation with alternative interaction partners. From it first reported in Molecular Cell in 2002 till now, this approach has been used on the networks of protein interaction in mammal cells, plant cells or even E.coli, and researches on transcription factors, G protein ?? dimmers, protein ubiqutination and so on.

Study on the transmission characteristics of genital Candida albicans infection by a rapid mi-crosatellite genotyping / 中华皮肤科杂志

Objectives In order to develop a rapid microsatellite genotyping assay for inter-strain differentiation of Candida albicans isolates and understand the transmission characteristics of the infections. Methods DNA was extracted from C. albicans isolates from genitals, anal canals and oral cavities of 39 women and 27 men with genital candidiasis. The microsatellite sequences in stabel genes(CDC3, EF3 and HIS3) were amplified by a fluorescence labeled PCR. Fluorescent signals were read with an automatic se- quencer, and the data were collected with GeneScan software followed by genotyping with Genotyper soft- ware to analyze polymorphic microsatellite loci. Results Combined analysis of the 3 microsatellite markers showed 18 gene allele associations in C. albicans from genital sites of all men and women, including 10 in women, 11 in men and 3 in both. The allele associations of dominant pathogenetic strains for both sexes were 116:124, 122:131,160:200, which covered 50% of pathogenetic infection. Three common allele associations for both sexes covered 71% of all infections. Genitals and anal canals shared strains of same allele associations in 80% of women and in only 3.8% of men. The strains of same allele associations were identified in both genitals and mouth in 2.7% of women but in none of men. In their genital sites 71% of couples shared the same allele strains, of which 80% were the dominant pathogenetic strains identified in both sexes. Conclusions The improved microsatellite genotyping assay is useful for rapid differentiation, identification of infective source, and contact tracing of C. albicans infection. There are pathogenetic C. albi- cans strains with predominant allele associations in genital infections.

Gene Disruption in Yeast / 生物化学与生物物理进展

Gene disruption by homologous recombination is a powerfu l tool for investigating gene function in yeast. Since 1980’s, it has been deve loped a lot. PCR-mediated gene disruption technique makes the manipulation easi er and it can be used to precisely delete genes in yeast. Multi-gene disruption technique can delete several genes successively in the same yeast strain. After the completion of the yeast Saccharomyces cerevisiae genome sequencing, the gene disruption technique for systematic analysis meets the need of the functio nal genomics in yeast. It also enlighten the study on human functional genomics.

Highly effective transformation of Cryptococcus neoformans / 第二军医大学学报

Objective: To establish a highly effective transformation method of Cryptococcus neoformans. Methods: Special reagents was used to make C. neoformans take in external DNA under given condition. This chemical transformation result was compared with that of electrotransformation. The feasibility of this chemical transformation was tested by plasmid stability test. Results: The efficiency of this chemical transformation was more than 103 transformants/?g plasmid DNA, far more than that of the traditional electrotransformation. Conclusion: An appropriate transformation method is established for C. neoformans transformation, which has high transformation efficiency.